Theresa May’s strategic aims, if that is quite the right way of describing them, are as follows. First, to avoid the UK having to participate in European elections after May 22. Second, to draw Labour into co-operating with her deal. Third, if that can’t be done, to ensure that they take the blame for not doing so. Fourth, if they are so drawn, to somehow keep her Party onside. Fifth, to try and head off Oliver Letwin and company from restricting her room for manoeuvre. Sixth and above all, to survive as Prime Minister. This is her chicken game.

At first glance, her statement this evening, coming in the wake of a mammoth Cabinet session, looks like business as usual. Corbyn will either be lured into signing off on her deal, thus having his fingerprints all over it (and sharing the blame among those who hate it). Or he will find reasons not to do so. In which case, he can be blamed for playing petty, partisan politics.

In that event, and assuming that the Speaker allows the deal to be put to the Commons, she will then gird up once again for that game of chicken. It’s my deal or my-deal-plus-something-else, she will warn the European Research Group. That something else could be a customs union or, just possibly, a Norway-type option. Or even, according to one reading of her words, a second referendum.

The ERG, as well as others, can count. Ken Clarke’s customs union motion yesterday failed by only three votes – by 273 to 276. Peter Kyle’s second referendum motion failed by 12. But it got more votes than Clarke’s proposal did, falling by 280 to 292. The Prime Minister’s deal fell last time round by 49, but got 286 votes – more than either of those other two options.

But though it may appears that “nothing has changed”, May’s words marked a very big policy shift indeed. Perhaps, if her deal comes back to the Commons, it will gain more votes than other options. (Who will select them, by the way?). But perhaps it won’t. In which case, this is the first time that “crucially” – as she put put it – “the Government stands ready to abide by the decision of the House”. [Our italics.]

In other words, if the Commons votes instead for a customs union, or for a revived Norway-type plan, or even arguably for a second referendum, the inference is that she would be willing to tack any of those objectives on to the Withdrawal Agreement. She thus seeks both to head off Letwin’s push for a Bill that would constrain her, and to give the EU reason to opt for a further limited extension.

However, there is an obvious tension between at least two of those six aims – namely, between ultimately letting opposition MPs help to decide Brexit policy, and satisfying Conservative MPs who want manifesto pledges honoured (and the referendum result respected). By reaching across the House, even in shadow form, many of those who make up the Party’s pro-Brexit majority will view her as a potential Robert Peel, ready to split her party to achieve a greater good, as she sees it. Her red lines, having turned pink, are dissolving altogether.

As we write, ERG reaction is, unsurprisingly, very hostile. No Cabinet member has resigned. But it is clear that this decision will have been contentious, and we await firm details. Initial EU reaction appears to be very doubtful – sceptical of whether the Prime Minister can get anything through the Commons fast enough to avoid those European elections. And what of her own survival? Unless she wins her chicken game fourth time round – or the EU itself delivers No Deal – she is heading at speed towards the slaughter house.